Q13) A solution is prepared from 26.2 x 10-5 kg of an known substance and 112.0 x 10-3 kg acetone at 313 K. The vapour pressure of pure acetone at this temperature is 0.526 atm. Calculate the vapourpressure of solution if the molar mass of substance is 273.52 X 10-3 kg mor. (Given the atomicmasses C = 12, H = 1, 0 = 16 )

Q13) A solution is prepared from 26.2 x 10-5 kg of an known substance

1.	Q13) A solution is prepared from 26.2 x 10-5 kg of an known substance and 112.0 x 10-3 kg acetone at 313 K. The vapour pressure of pure acetone at this temperature is 0.526 atm. Calculate the vapourpressure of solution if the molar mass of substance is 273.52 X 10-3 kg mor. (Given the atomicmasses C = 12, H = 1, 0 = 16 )
Answer» ANSWERThe molar mass M 2 of non-volatile substance can be calculated from the following formula.P 0 p 0 −p = W 1 ×M 2 W 2 ×M 1 Here, p 0 vapour pressure of acetone and p is the vapour pressure of the solution.M 1 and W 1 are the molar mass and mass of acetone.M 2 and W 2 are the molar mass and mass of a non-volatile substance.Substitute values in the above expression.185185−183 = 100×M 2 1.2×58 HENCE, M 2 =64.38g/mol.Thus, the molar mass of the non-volatile substance is 64 g/mol (APPROXIMATELY).